Core B ? Abstract In this adjuvant-enhanced and electroporation-delivered DNA prime-protein boost HIV vaccine development program, the availability of high-quality and well-developed recombinant Env protein vaccine components are critical to the success of entire program. Core B is designed to provide non-GMP recombinant Env proteins for proposed pre-clinical animal studies, including non-human primate studies, and to advise on scientific and technical issues related to the production of GMP-grade recombinant Env proteins for planned phase I clinical studies. The PI of Core B, Dr. Shan Lu, has developed a polyvalent gp120 protein formulation from his previous NIH-funded programs. That formulation includes four recombinant gp120 proteins (covering HIV-1 subtypes A, B, C, and AE) produced using the CHO system under GMP conditions.